Ruptured Giant Basilar Artery Aneurysm in a Comatose Adolescent: Successful Obliteration Using Intraoperative SSEP, BAER, and MEP Monitoring. A Case Report

SUMMARY

Giant basilar aneurysms are infrequently seen in children. We present the endovascular management of an adolescent who presented comatose with pinpoint pupils due to a ruptured giant basilar trunk aneurysm. A noncontrast head CT disclosed a large prepontine lesion with brainstem hemorrhage. Catheter angiography showed a 4.5 cm irregular, fusiform basilar trunk aneurysm. With SSEP, BAER, and MEP monitoring, the patient underwent bilateral temporary vertebral artery occlusion, followed by GDC embolization of the aneurysm. Postprocedure internal carotid angiograms showed adequate blood supply to the basilar apex via patent posterior communicating arteries. On postprocedure day two, the patient was following commands. The remainder of his hospital course was uneventful. Postoperative angiograms showed no residual filling of the aneurysm. At 12 months the patient was neurologically intact and at baseline function as an honor student and follow-up angiogram showed persistent occlusion of the aneurysm from the circulation. Successful endovascular treatment has been considered a less invasive and safer alternative to surgical management of some complex vascular lesions. While most reports on reversing basilar artery flow have been carried out in awake patients with neurological examinations, this is not possible in a patient presenting in a comatose state. This report suggests that SSEPs, BAERs and MEP may be of use in such patients in safely carrying out basilar artery occlusion.

Role of intraoperative angiography in the surgical treatment of cerebral aneurysms

The benefit of using intraoperative angiography (IA) during aneurysm surgery is still uncertain.

OBJECT

In this prospective study, the authors evaluate the radiographically demonstrated success of surgical treatment in 151 consecutive patients harboring 173 aneurysms who selectively underwent IA examination. The authors also assess the frequency with which IA led to repositioning of the aneurysm clip.

METHODS

Intraoperative angiography was used selectively in this series, based on the surgeon's concern about the potential for residual aneurysm, distal branch occlusion, or parent vessel stenosis. Specific variables were analyzed to determine their impact on the incidence of clip repositioning and the accuracy of IA was evaluated by direct comparison with postoperative angiography (PA) in 90% of the cases in which IA was used.

CONCLUSIONS

The selective use of IA led to successful treatment as shown by PA, with a low incidence of unexpected residual aneurysm (3.2%), distal branch occlusion (1.9%), and parent vessel stenosis (0%). Intraoperative angiography led to immediate repositioning of the aneurysm clip in 27% of the cases. Anterior cerebral artery aneurysms required clip repositioning less often and superior hypophyseal artery aneurysms required repositioning more often than aneurysms in other locations. Large and giant aneurysms required clip repositioning more often than small aneurysms; however, they were also more likely to display false success on IA as determined by PA. Aneurysms arising along the internal carotid artery were more likely to display successful clipping on IA, as determined by PA, than were aneurysms in other locations. The results of this series support the selective use of IA in the treatment of complex aneurysms, particularly large and giant aneurysms as well as superior hypophyseal artery aneurysms. As measured by PA, IA will improve the outcome of these patients.

Reducing the risk of rebleeding before early aneurysm surgery: a possible role for antifibrinolytic therapy

Previous studies on the initial nonoperative management of aneurysmal subarachnoid hemorrhage (SAH) demonstrated that antifibrinolytic therapy reduced the risk of rebleeding by approximately 50%; however, prolonged antifibrinolytic treatment was associated with an increase in the incidence of hydrocephalus and delayed ischemic deficit. When early surgical intervention became routine for ruptured aneurysms, the use of antifibrinolytic therapy diminished. However, early surgery is generally performed in the first several days after SAH and the risk of rebleeding remains until the aneurysm is obliterated. Based on a review of the literature, the authors formed two hypotheses: 1) the high-dose intravenous administration of epsilon-aminocaproic acid (EACA), an antifibrinolytic agent, might reduce the risk of recurrent hemorrhage in the interval between SAH and early surgical intervention, and 2) a short course of EACA might not produce the increase in complications previously associated with its prolonged administration. The use of preoperative high-dose EACA therapy was evaluated in 307 patients to determine its safety and efficacy in reducing the incidence of rebleeding before early aneurysm surgery. All patients were admitted within 3 days of their SAH and were classified as Hunt and Hess Grades I to III. Only four patients (1.3%) suffered a recurrent hemorrhage. This compares favorably to the rebleeding rate of 5.7% reported for the early surgery group in the International Cooperative Study on the Timing of Aneurysm Surgery. The incidence of hydrocephalus or symptomatic vasospasm was not unduly elevated in patients receiving preoperative EACA. Thirty-five patients (11.4%) needed temporary cerebrospinal fluid drainage during their hospitalization and, overall, 8.8% required a ventriculoperitoneal shunt. The mean age of the patients who required a shunt was nearly 10 years older than the general study population. Seventy-one patients (23%) developed symptomatic vasospasm and 8.1% suffered a stroke. This study indicates that a brief course of high-dose EACA is safe and may be beneficial in diminishing the risk of rebleeding in good-grade patients prior to early surgical intervention. Further investigation is planned based on these promising results.

Retrograde suction decompression of an ophthalmic artery aneurysm using balloon occlusion. Technical note

A large ophthalmic artery aneurysm was ligated using a modification of the retrograde suction technique described by Batjer and Samson. Temporary proximal occlusion of the internal carotid artery was accomplished with a double-lumen balloon catheter, and distal occlusion was performed with a temporary clip. The aneurysm was collapsed by gentle aspiration through the distal lumen of the balloon catheter. This greatly facilitated dissection and clip ligation of the aneurysm.

Pathophysiology and treatment of subarachnoid hemorrhage

The pathophysiology and treatment of acute subarachnoid hemorrhage (SAH) are reviewed. SAH occurs when blood is released into the subarachnoid space, which surrounds the brain and spinal cord. Symptoms of SAH include severe headache, nausea, vomiting, neck pain, nuchal rigidity, and photophobia. The initial hemorrhage is fatal in 20-30% of patients. Complications of SAH include rebleeding, hydrocephalus, delayed cerebral ischemia associated with cerebral vasospasm, and seizures. The likelihood of rebleeding is increased by measures that rapidly lower intracranial pressure. The risk of developing hydrocephalus is associated with the volume of blood within the subarachnoid space and ventricular system. Cerebral vasospasm develops in 20-40% of patients, and up to 50% of affected patients die or suffer permanent neurological damage. Seizures occur in 5-15% of patients with SAH. Radiologic procedures form the foundation for the diagnosis of SAH. The most commonly used rating scale classifies the severity of SAH based on the clinical presentation of the patient. Surgery is the definitive treatment for the prevention of rebleeding. Hydrocephalus can only be treated surgically, most commonly by insertion of a drain. The only measures proved to be effective for treatment of delayed cerebral ischemia are volume expansion and the induction of hypertension. The calcium-channel blocker nimodipine was recently approved for treatment of arterial spasm in SAH. Intravenous nicardipine is also being studied for the same indication. These agents may improve clinical outcome substantially by limiting fixed neurological deficits. To prevent seizures, prophylactic antiepileptic therapy with phenytoin sodium is generally accepted. The SAH complications of rebleeding, hydrocephalus, delayed cerebral ischemia, and seizures are managed by surgical, drug, and fluid therapy.